In a circuit breaker, a compression chamber is used in order to compress a quantity of dielectric gas filling the compression chamber, in order to blast an electric arc forming between two contacts of the circuit breaker, during a separation operation of the contacts.
In a known embodiment, for example in document FR2435795, the compression chamber comprises a cylinder and a piston which are in gastight contact with each other and which bound the compression chamber.
During the separation operation, the cylinder and the piston move in opposite direction one respective to the other.
The relative speed of displacement of the piston with respect to the cylinder equals the sum of the speed of both these components relative to a stationary frame of the circuit breaker.
Such speed is relatively high, this generates important friction between the cylinder and the guiding of the piston with respect to the stationary frame is relatively complex due to the radial tolerance stack.
Embodiments of the invention aim to propose a circuit breaker wherein the friction between the different parts is lowered in relation to the prior art.